Do mushrooms spread in town? I've built a small automatic mushroom farm on my res with around 120 mushrooms growing in it. I know mushrooms spread very rarely* but I've been afk by the farm for a few hours and haven't got a single mushroom harvested. I'm wondering if there's any change to the regular spreading algorithm in town. *For reference the regular mushroom spreading algorithm is as follows. Each game tick 3 random blocks in each 16x16x16 sub-chunk receive an update. If a mushroom receives an update it has a 1/100 chance of choosing a random block in a 3x3x3 centred on the mushroom. If the mushroom chooses a block which a mushroom can be placed, then a mushroom spreads to this location. In my farm design, each mushroom can spread to 3 different blocks. With this in mind I was expecting around 2 mushrooms per hour.
Mushrooms will grow in town. By default, I don't think that any environmental features other than mob spawning are disabled. EDIT: Someone should fact check this, but I believe that mushrooms only grow in dark environments. It's also recommended to start off with a larger amount of mushrooms across a larger area, because that will significantly increase the amount of mushrooms you'll get at any given time.
you need a bigger then 3x3x3 area. Mushrooms will only spread if there are fewer than 5 mushrooms in an area of 9x9x3(L, W, H) around the original mushroom. http://minecraft.gamepedia.com/Tutorials/Mushroom_farming
Mushrooms will not grow if the light level is greater than 12 unless they are planted on Podzol or Mycelium. This is according to the minecraft wiki
